Our objectives are to expand and better correlate ongoing basic and applied research into the nature and treatment of sickle cell anemia and ongoing community screening and counseling programs. A large scale definitive screening program utilizing hemoglobin electrophoresis is underway and will be expanded and long range evaluation established. Applied research relevant to the effect of quality of health care, therapy and cause of leg ulcers, causes and therapy of painful crisis will be expanded and initiated. Basic studies of the molecular modification of sickle hemoglobin will be expanded, the cause of infection in patients with sickle cell anemia will be studied and approaches to pre-natal diagnosis explored. Studies directed at defining the pathophysiologic role played by coagulation mechanisms during sickle cell crisis are also proposed.